【简答题】Questions 18~21 are based on the following dialogue in a travel agency. Which city is the man going to visit? [A] Oxford. [B] Paris. [C] Shaftsbury. [D] London.
【单选题】A certain water delivery pipeline uses an IS50-32-200 centrifugal pump to send the water in the low-level open trough to the open trough which is 3 m higher than the low-level open trough. After the v...
【单选题】A rock is thrown off a 30 m cliff at a 45° angle above the horizontal. Which is the following is true regarding the acceleration of the rock? (air resistance is negligible)
A.
The acceleration will be of magnitude g and have both horizontal and vertical components.
B.
At the peak of the rock’s path, the magnitude of acceleration will be half of what it was when the rock was initially thrown.
C.
The acceleration will be of magnitude g and in a downward direction.
D.
The acceleration will be downward during the rock’s ascent and upward during the rock’s descent.
E.
The acceleration will increase throughout the rock’s flight .